diff mbox series

[v4,18/25] PCI: pciehp: Use PCI_POSSIBLE_ERROR() to check read from hardware

Message ID e185b052fbfd530df703a36dd31126cb870eed95.1637243717.git.naveennaidu479@gmail.com (mailing list archive)
State Accepted
Headers show
Series Unify PCI error response checking | expand

Commit Message

Naveen Naidu Nov. 18, 2021, 2:03 p.m. UTC 
An MMIO read from a PCI device that doesn't exist or doesn't respond
causes a PCI error.  There's no real data to return to satisfy the
CPU read, so most hardware fabricates ~0 data.

Use PCI_POSSIBLE_ERROR() to check the response we get when we read
data from hardware.

This helps unify PCI error response checking and make error checks
consistent and easier to find.

Compile tested only.

Acked-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com>
---
 drivers/pci/hotplug/pciehp_hpc.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 83a0fa119cae..e94914e50fca 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -89,7 +89,7 @@  static int pcie_poll_cmd(struct controller *ctrl, int timeout)
 
 	do {
 		pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
-		if (slot_status == (u16) ~0) {
+		if (PCI_POSSIBLE_ERROR(slot_status)) {
 			ctrl_info(ctrl, "%s: no response from device\n",
 				  __func__);
 			return 0;
@@ -165,7 +165,7 @@  static void pcie_do_write_cmd(struct controller *ctrl, u16 cmd,
 	pcie_wait_cmd(ctrl);
 
 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
-	if (slot_ctrl == (u16) ~0) {
+	if (PCI_POSSIBLE_ERROR(slot_ctrl)) {
 		ctrl_info(ctrl, "%s: no response from device\n", __func__);
 		goto out;
 	}
@@ -236,7 +236,7 @@  int pciehp_check_link_active(struct controller *ctrl)
 	int ret;
 
 	ret = pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
-	if (ret == PCIBIOS_DEVICE_NOT_FOUND || lnk_status == (u16)~0)
+	if (ret == PCIBIOS_DEVICE_NOT_FOUND || PCI_POSSIBLE_ERROR(lnk_status))
 		return -ENODEV;
 
 	ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
@@ -443,7 +443,7 @@  int pciehp_card_present(struct controller *ctrl)
 	int ret;
 
 	ret = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
-	if (ret == PCIBIOS_DEVICE_NOT_FOUND || slot_status == (u16)~0)
+	if (ret == PCIBIOS_DEVICE_NOT_FOUND || PCI_POSSIBLE_ERROR(slot_status))
 		return -ENODEV;
 
 	return !!(slot_status & PCI_EXP_SLTSTA_PDS);
@@ -621,7 +621,7 @@  static irqreturn_t pciehp_isr(int irq, void *dev_id)
 
 read_status:
 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status);
-	if (status == (u16) ~0) {
+	if (PCI_POSSIBLE_ERROR(status)) {
 		ctrl_info(ctrl, "%s: no response from device\n", __func__);
 		if (parent)
 			pm_runtime_put(parent);